Modems; Antenna parameter measuring apparatus; Antennas for radio, for television; Anti-intrusion alarms; Apparatus for recording, transmission or reproduction of sound; Audio amplifiers; Broadband radios; Communication modems; Electronic detectors for observing and measuring the infrared spectrum, namely, infrared detectors; Electronic devices used to locate lost objects employing radio frequency; Fingerprint imagers; Flue gas analyzers; Frequency meters; Frequency synthesizers